Nutritional product for persons infected with human immunodeficiency virus

ABSTRACT

An enteral nutritional product for persons infected with human immunodeficiency virus contains a soy protein hydrolysate having a degree of hydrolysis in the range of about 14 to 17 and a molecular weight partition, as determined by size exclusion chromatography, wherein 30-60% of the particles have a molecular weight in the range of 1500-5000 Daltons. The nutritional product also contains a source of intact protein. The nutritional product has a ratio, by weight, of n-6 to n-3 fatty acids of about 1.3:1 to 2.5:1. The nutritional product also contains a source of dietary fiber.

FIELD OF THE INVENTION

The present invention relates generally to a liquid enteral nutritionalproduct which has been formulated to address the nutritional needs ofpersons infected with human immunodeficiency virus (HIV).

BACKGROUND OF THE INVENTION

A profound wasting disease in humans associated with Pneumocystiscarinii pneumonia was first described in the United States in 1981. Theinvestigation of the symptoms associated with this disease ultimatelyfocused public health and political structures on a disease described asacquired immunodeficiency syndrome (AIDS). AIDS is defined by infectionwith the human immunodeficiency virus (HIV), and by the onset of severalopportunistic infections, syndromes, and/or malignancies. These include,but are not limited to, tuberculosis, Pneumocystis carinii pneumonia,Salmonella bacteremia, Kaposi's sarcoma, Mycobacterium aviumintracellulare, herpes simplex, toxoplasmosis, cytomegalovirus (CMV),dementia complex, and wasting syndrome.

The cell types infected by HIV play a role in defining the efforts ofthe virus on patterns of infection, and ultimately the effect of thedisease on the metabolic and nutritional state of a person infected withHIV. The immune system develops several types of cells to deal withinfection, including B and T lymphocytes, which produce antibodies anddirectly attack the invading pathogen. These cells and others, includingmacrophages, monocytes, and other cell types involved in the immuneresponse, communicate through protein factors which they secrete(cytokines) and/or through the types of proteins and glycoproteins theydisplay on their surface.

Health care professionals dealing with HIV-positive and AIDS patientsface a multitude of management issues, including control ofopportunistic infections and malignancies. Two major factors underlyinghow a patient may respond to the therapies required to manage thedisease are: (a) the nutritional status of the patient early in theinfectious process, and (b) the ability of the patient to take in andtolerate adequate nutrition.

There is disclosed herein a liquid nutritional product for enteralfeeding which is formulated, on the basis of the latest and mostcompelling research, to meet the specific nutrient needs of personsinfected with HIV. This calorie and nutrient-dense, low fat nutritionalproduct contains enterotrophic peptides, a fat source high in omega-3fatty acids, and fiber. Enterotrophic peptides appear to modulate aparticular receptor pathway in cells which reduces the expression ofapoptotic genes and alters the phosphorylation of cell division controlprotein. The peptides significantly reduce the expression of theapoptotic-associated gene, amyloid beta precursor protein, and apoptoticrescue protein. (This protein is a marker for the induction of celldeath). This nutritional regimen results in a reduction in the rate ofintestinal cell death.

These formula components promote changes in the gastrointestinal tractthat result in improved nutritional and physiological status for aHIV-infected person. The vitamin and mineral profile of this nutritionalproduct provides for repletion of the nutrients for which HIV-positivepersons have been shown to be at risk of depletion or deficiency. Thenutritional product also contains β-carotene.

The nutritional product of the present invention is acceptable totalenteral support and may be consumed, either orally or by tube feeding.Flavor variety, Orange Cream and Chocolate flavors are disclosed herein,promotes compliance when the nutritional product is used as an oralsupplement or as a total oral diet when a person's condition precludesintake of solid foods.

DISCUSSION OF PRIOR ART

There has been a great deal written about nutritional support of personsinfected with HIV.

Villous atrophy of the small intestine may be detected early in thecourse of HIV infection and in the absence of enteropathogens, so it hasbeen postulated that the intestinal tract may be severely affected byHIV. The histological appearance of villous atrophy seen in HIVinfection is unlike the classic villous atrophy seen in gluten-sensitiveenteropathy or tropical sprue because the enterocytes appear normal andthere is no increase in intraepithelial lymphocytes. This resembles thevillous atrophy seen in graft versus host disease of bone marrowtransplantation, and this raises the possibility that an immune responsewithin the mucosa may be responsible. Griffin, "Human ImmunodeficiencyVirus Infection and the Intestine", BAILLIERE'S CLINICALGASTROENTEROLOGY", Vol. 4, No. 3, pages 657-673 (1990). Apoptosis ofcrypt cells in AIDS patients was reported soon after the disease wasidentified. Kotler et al., "Enteropathy Associated with the AcquiredImmunodeficiency Syndrome", ANNALS OF INTERNAL MEDICINE, Vol 101, No. 4pages 421-428 (1984).

Trujillo et al, "Assessment of nutritional status, nutrient intake, andnutrition support in AIDS patients", JOURNAL OF THE AMERICAN DIETETICASSOCIATION, Vol.92, No.4, pages 477-478 (1992) reports observationsthat hospitalized AIDS patients can consume only 70% of estimated basalenergy needs and 65% of protein needs, which does not account for theincreased needs of hypermetabolism associated with acute infection orany physical activity. Patients with AIDS have moderate to severemetabolic stress similar to that found in other critically ill patients.This stress, coupled with the anorexia and malabsorption associated withthe disease, promotes malnutrition. Irrespective of any possiblespecific relationship between nutrition and the HIV disease process,malnourished patients will be debilitated and unable to functionoptimally. Malnutrition in general affects five areas of functionality:reproductive competence, immunocompetence, work performance and/orbehavioral performance and cognition. THE FASEB JOURNAL, Vol. 5, No. 10,pages 2329-2330, at page 2330 (1991)

Food-borne infections must be scrupulously avoided in immunosupressedpatients, because what would be a minor incident for a healthy personmight become life threatening. HIV infected patients are 300 times moresusceptible to salmonella than healthy persons if they ingestcontaminated food. Dwyer, "Nutrition Support of HIV+Patients", HENRYFORD HOSPITAL MEDICAL JOURNAL, Vol. 39, No. 1, pp. 60-65, at page 62(1991). Kotler, "Nutritional Effects and Support in the Patient withAcquired Immunodeficiency Syndrome", JOURNAL OF NUTRITION, March, 1992(3rd supplement), pages 723-727 describes some micronutrientdeficiencies in AIDS patients: (a) low serum zinc and selenium; (b)vitamin B-12 malabsorption and subnormal serum vitamin B-12concentrations; (d) the prevalence of folate deficiency which variesdepending upon the dietary habits of the affected population; and (d)malabsorption of fat-soluble micronutrients, such as vitamin E,β-carotene and essential fatty acids.

In a letter to the editor in the AMERICAN JOURNAL OF GASTROENTEROLOGY,Vol. 85, Issue 4, pp. 475 (1990), Freed et al champions the use ofenteral nutritional support for AIDS and cancer patients, as opposed toparenteral feeding, whenever possible.

The administration of specific nutrients or diets including essentialfatty acids, Cobalamin, and zinc has been attempted in patients withAIDS-related complex (ARC) or AIDS because biochemical indicators ofthese nutrients are altered for the worse in symptomatic HIV infectedpatients. However, little symptomatic improvement or amelioration inimmune status was demonstrated. Dwyer, "Nutrition Support ofHIV+Patients", HENRY FORD HOSPITAL MEDICAL JOURNAL, Vol. 39, No. 1, pp.60-65, at page 60 (1991).

Mandau et al., "USE OF A FIBER-CONTAINING ENTERAL FORMULATION IN AN AIDSPATIENT", Nutrition Clinical Practice, Vol. 4, Issue 4, pp. 136-139(1989) describe an AIDS patient who was fed a variety of nutritionalsupplements, but continued to suffer from bad diarrhea until fed a highresidue nutritional product. However, King et al, "LESS DIARRHEA SEEN INHIV-POSITIVE (HIV+) PATIENTS ON A LOW-FAT, ELEMENTAL DIET", PROCEEDINGSOF THE V INTERNATIONAL CONFERENCE ON AIDS, page 466 (1989) suggests thatdietary management with a low-fat, low-residue, elemental diet may be auseful adjunctive therapy to help maintain body weight and reducediarrhea in some HIV infected patients.

The desirability of a diet for AIDS patients which is low in fat buthigh in fiber is suggested by Weaver in "Reversible Malnutrition InAIDS", GASTROENTEROLOGY CLINICS OF NORTH AMERICA, Vol. 17, No. 3, pp.545-561 (1988). Weaver teaches that Vivonex® TEN (manufactured byNorwich Eaton Chemicals, Inc., Norwich, N.Y.), has proved to be anexcellent supplement or diet for AIDS patients with normal orcompromised gut function. Vivonex® is packaged in powdered form and ismixed with water or a liquid of choice (to modify the bitter taste ofthe amino acids) for oral consumption or tube feeding. This publicationalso presents other several suggested regimens for nutritional supportfor AIDS patients, but concludes, at page 559 that "there is no singlenutritional therapy regimen that can be utilized in the treatment of allof these patients. Therefore, we recommend special individualized oraldiets combined with food supplements and enteral and parenteral diets inthe treatment of ARC/AIDS patients."

Hickey, "Nutritional Support of Patients with AIDS", SURGICAL CLINICS OFNORTH AMERICA, Vol. 71, No. 3, pages 645-664 (1991) presents a goodreview of the state of nutritional support for AIDS patients. He statesthat the primary goal of nutritional therapy for these patients is tomaintain metabolic homeostasis (normal functional indices, positivenitrogen balance, and a stable weight). He advocates feeding anelemental nutritional product, which contains protein in the form offree amino acids, either as a supplement or sole source of nutrition,because the free amino acids having molecular weights of less than 500are absorbed rapidly in the presence of compromised gut function.However, he also indicates that not all AIDS patients are able totolerate an elemental nutritional product. Hecker et al, "Malnutritionin Patients with AIDS", NUTRITION REVIEWS, Vol 48 No 11, pages 393-401,at page 397 (1990) suggests that the consumption of a low-fat, lowresidue elemental diet may be beneficial for some AIDS patients.

The recommendations to feed a free amino acid elemental diet to AIDSpatients are not without controversy. For instance Brolin et al., "Useof Nutrition Support in Patients with AIDS: A Four-Year RetrospectiveReview", NUTRITION, Vol. 7, No. 1, pages 19-22, at page 21 (1991) notesthat authors such as Hickey and Weaver did not describe the results oftheir use of elemental diets in AIDS patients with diarrhea. In Brolinet al's experience such patients will not drink sufficient quantities ofany enteral diet and do not tolerate enteral tube feedings because ofexacerbated gut dysfunction, such that in their experience parenteralnutritional support has been the only useful option in AIDS patientswith diarrhea.

There are some compelling arguments against feeding an elemental diet toan AIDS patient. While not specifically directed to AIDS patients, Kleinet al, "The Role of Cell Renewal in the Ontogeny of the Intestine. II.Regulation of Cell Proliferation in Adult, Fetal and NeonatalIntestine", JOURNAL OF PEDIATRIC GASTROENTEROLOGY AND NUTRITIONVol. 2,pages 204-228, at page 211 (1983) relates that (a) an elemental diet(VIVONEX®) has been shown to decrease cell renewal and villus size inboth the jejunum and ileum; (b) the addition of bulk to the elementaldiet does increase cell renewal, but does not alter villus height; and(c) gastrin levels are drastically lowered in elemental diet-fed rats,but it is possible that there is more direct effect of dietaryconsistency on the mucosa.

While not specifically directed to AIDS patients, the effects of dietupon chemotherapy induced enterocolitis are reported in Shou et al.,"Dietary Manipulation of Methotrexate-Induced Enterocolitis", JOURNAL OFPARENTERAL AND ENTERAL NUTRITION, Vol. 15, No. 3, pages 307-312 (1991).The results of this study suggested that patients unable to ingest aregular diet while undergoing chemotherapy may benefit from a diet withpolypeptides as a nitrogen source rather than an elemental diet. Thispublication advocates that elemental liquid diets cause changes inintestinal microflora characterized by a significantly increased levelof Gram-negative bacteria. it is alleged that translocation of bacteriafrom the intestinal tract through the epithelial mucosa to causeinfections may result at least in part from bacterial overgrowth andthat administration of a liquid nutritional diet results in atrophy ofthe intestinal mucosa with reduced mucosa villous height and crypt depthand other undesirable results.

DETAILED DESCRIPTION OF THE INVENTION

A nutritional product according to the present invention is a highprotein, low fat, calorically dense product for HIV infected and AIDSpatients. The nutritional product of the present invention meets theunique nutrient requirements of this population. An objective of thepresent invention is to maintain the gut architecture of the HIVinfected person in a state which is at least equal to normal gutarchitecture relative to a disease state. Other objectives of thepresent invention are a reduction in the potential for dehydration, anda reduction in the amount of medication needed for treating diarrhea,which reduces the likelihood of interaction between anti-diarrheamedications and other medications that the HIV infected person may beusing. The maintenance of gut architecture lessens or eliminates aninflammatory response in the form of enteritis. Histological andendoscopic evaluations of HIV infected persons who had been fed thenutritional product of the present invention indicated that the abovedescribed benefits had been manifested. Yet another objective of thepresent invention is to impede the deterioration of the immune system ofan HIV infected person.

The nutrient base for the enteral liquid nutritional product of thepresent invention is 1515 calories per day which are provided in five 8fluid ounce servings. However, it is understood that the enteral liquidnutritional product may be consumed either as a sole source of nutritionor as a nutritional supplement, as recommended by an attendingphysician. Put another way, an 8 fluid ounce serving of the newnutritional product provides about 303 calories and a liter providesabout 1,280 calories. The caloric density of the new nutritional productis in the range of about 1.2 to 1.35 cal/ml, most preferably about 1.28cal/ml. This high caloric density allows the patient to consume morecalories in a smaller volume of product, which is extremely important ininstances of impaired appetite. The nutritional profile of the newenteral nutritional product is presented in TABLE 1.

                                      TABLE 1                                     __________________________________________________________________________    NUTRITIONAL PROFILE OF PRODUCT                                                         TARGET PER                                                                            TARGET RANGE                                                                            TARGET PER                                         NUTRIENT LITER   PER LITER 8 FLUID OUNCE                                      __________________________________________________________________________    Fat, g   22.8    22.8-24.8 5.4                                                Protein, g                                                                             60.0    60.0-62.7 14.2                                               Carbohydrate, g                                                                        215.8   200-225   49.0                                               Vitamin A, IU                                                                          4223    4223-7580 1000                                               β-carotene, mcg                                                                   5068    5068-7000 1200                                               Vitamin E, IU                                                                          38.1    38.1-53   9                                                  Vitamin D, IU                                                                          338     338-485   80                                                 Vitamin K, mcg                                                                         67.6    67.6-160  16                                                 Calcium, mg                                                                            845      845-1268 200                                                Magnesium, mg                                                                          338     338-507   80                                                 Sodium, mg                                                                             1014     913-1115 235                                                Potassium, mg                                                                          2619    2357-2881 635                                                Phosphorus, mg                                                                         845      845-1268 200                                                Chloride, mg                                                                           1479    1331-1627 345                                                Iodine, mcg                                                                            127     127-191   30                                                 Zinc, mg 15.9    15.9-23.7 3.75                                               Copper, mg                                                                             2.54    2.54-3.8  0.6                                                Manganese, mg                                                                          5.28    5.28-7.9  1.25                                               Iron, mg 19.1    19.1-28.5 4.5                                                Selenium, mcg                                                                          60       60-203   14                                                 Chromium, mcg                                                                          85       85-203   20                                                 Molybdenum, mg                                                                         127     127-253   30                                                 Pyridoxine                                                                             3.38    3.38-5.3  0.8                                                (B.sub.6), mg                                                                 Niacin, mg                                                                             25.4    25.4-49   6                                                  Pantothenate,                                                                          12.7    12.7-29   3                                                  mg                                                                            Folic Acid, mcg                                                                        507      507-1075 120                                                Thiamine (B.sub.1),                                                                    3.17    3.17-8.0  0.75                                               mg                                                                            Riboflavin                                                                             2.88    2.88-6.2  0.68                                               (B.sub.2), mg                                                                 Cyanocobalamin                                                                         50.68   50.68-97  12                                                 (B.sub.12), mcg                                                               Biotin, mcg                                                                            381     381-950   90                                                 Vitamin C, mg                                                                          381     381-825   90                                                 Choline, mg                                                                            212     212-750   50                                                 Taurine, mg                                                                            212       212-320.4                                                                             50                                                 Carnitine, mg                                                                          127       127-299.4                                                                             30                                                 Fiber, g 8.9      8.9-11.6 2.1                                                __________________________________________________________________________

Body protein stores are in a constant state of breakdown (catabolism)and synthesis (anabolism), a process known as protein turnover. Personswith HIV infection experience metabolic "ebbs" and "flows" from theeffect of ongoing and intercurrent infection. During active phases ofinfection, when patients are hypermetabolic, catabolic processesdominate. During quiescent phases between active and intercurrentinfection, anabolism predominates. Providing appropriate levels ofenergy, protein and other nutrients enhances nitrogen and tissuesynthesis during anabolism. It has been reported that enteral nutritionsupport can replete body-cell mass in malnourished AIDS patients.

The protein system in a preferred embodiment of the nutritional productof the present invention comprises by weight: about 78% soy proteinhydrolysate and about 22% sodium caseinate.

The soy protein hydrolysate which is used as a source of protein in thenutritional product of the present invention may be manufactured using aprocess taught in U.S. Pat. No. 4,100,024, which is incorporated hereinfor the purpose of teaching a process for manufacturing a soy proteinhydrolysate for use in the nutritional product of the present invention.Briefly, this is a process for the preparation of polypeptides from soyprotein soluble in aqueous media at pH's in the range of 2 to 7 whichinvolves: hydrolyzing soy protein with a microbial, alkaline proteinasein a concentration ranging from 4 to 25 Anson units per kg of soyprotein at a substrate concentration of between 5 and 20% w/w soyprotein, at a pH in the range of from 7.5 to 8.5, until a degree ofhydrolysis in the range of from about 8 to 15% is attained, whereafterthe enzyme is inactivated by reduction of pH with a food grade acid,then recovering the supernatant from the precipitate. However, it isunderstood that a soy protein hydrolysate produced by any other processwhich has the characteristics elaborated upon herein may be used in thepractice of the present invention.

An example of a nutritional product containing such a soy proteinhydrolysate is taught in U.S. Patent 4,959,350, but this prior artnutritional product has a pH of lower than 4.5 (as compared to a pH of6.4 to 6.6 in the product of the present invention) and has anosmolality of below about 350 mosm/kg water (as compared to about 660mosm/kg water in the nutritional product of the present invention). Thisprior art nutritional product may be further distinguished from thenutritional product of the present invention by the fat composition,fiber content, and the vitamin and mineral profiles of the product ofthe present invention.

The nutritional product of the present invention has been manufacturedusing soy protein hydrolysate obtained from NOVO Industri A/S,Bagsvaerd, Denmark, who manufactured the soy protein hydrolysateaccording to the above described process. The properties of a soyprotein hydrolysate which is suitable for use in the practice of thepresent invention have been determined by actual analysis of samplesfrom several lots of soy protein hydrolysate obtained from NOVOIndustries and/or specifications selected in accordance with desiredproperties.

It is believed to be very important that the soy protein hydrolysateused in the practice of the invention comprise, by weight, not less than76%, preferably not less than 80% protein, not more than 1% fat, and notmore than 5.5%, preferably not more than 4.8% ash. It is also believedto be very important that a 5% slurry (by weight) of the soy proteinhydrolysate in water has a pH in the range of about 4.2 to 4.3, but inany instance less than 4.5. It is believed to be important that thedegree of hydrolysis of the soy protein hydrolysate (AN/TN X 100) be inthe range of about 14 to 17 and most preferably about 16.

The amino acid profile of the soy protein hydrolysate that has been usedin the practice of the present invention is presented in Table 2, andthe mineral profile is presented in Table 3. The molecular weightprofile is presented in Table 4 for soy protein hydrolysate (SPH) havingabout a 16% degree of hydrolysis with the approximate molecular weightpartition determined by size exclusion chromatography of samples from 4lots of SPH. The molecular weight profile of the soy protein hydrolysateis believed to be very important because particles sizes are related tothe physical stability and biological functionality of an enteralnutritional product which contains the SPH. That is to say, for the SPHused in the nutritional product of the present invention the molecularweight profile indicates a large peptide content (consisting ofparticles having a molecular weight of 1500-5000 Daltons) and a smallfree amino acid content. About 30-60%, by weight, of the SPH comprisesparticles having molecular weights of 1500-1500 Daltons. The free aminoacid content is less than 1%, by weight of the soy protein hydrolysate,or put another way less than 1 g/100g of the soy protein hydrolysate.Preferably, the enteral nutritional product of the invention contains noother source of free amino acids. However, it is within the scope of theinvention for the nutritional product to contain up to about 13 g/100 gof protein as free amino acids. The low free amino acid content is anadvantage for osmolality and flavor characteristics of an enteralnutritional product. The mineral profile of the soy protein hydrolysateis believed to be very important because it supplies most of the traceand ultratrace minerals in the nutritional product.

                  TABLE 2                                                         ______________________________________                                        AMINO ACID PROFILE OF SOY PROTEIN                                             HYDROLYSATE (g/100 g)                                                         ______________________________________                                        Aspartic acid     9.8-10.4                                                    Threonine        2.9-3.2                                                      Serine           3.7-4.4                                                      Glutamic Acid    17.0-18.1                                                    Proline          4.4-4.9                                                      Glycine          3.2-3.3                                                      Alanine          3.0-3.2                                                      Valine           2.9-3.6                                                      Methionine       0.9-1.1                                                      Isoleucine       3.0-3.7                                                      Leucine          5.1-5.3                                                      Tyrosine         2.7-2.9                                                      Phenylalanine    3.3-3.5                                                      Histidine        2.0-2.2                                                      Lysine           5.5-5.8                                                      Arginine         6.3-6.7                                                      Tryptophan       0.3-0.7                                                      Cystine          1.3-1.4                                                      Free Amino Acids 0.4-0.7                                                      ______________________________________                                    

                  TABLE 3                                                         ______________________________________                                        MINERAL PROFILE OF SOY PROTEIN HYDROLYSATE                                                  Preferred                                                                             Most Preferred                                                        Range   Range                                                   ______________________________________                                        Calcium, mg/100 g                                                                             170-350   170-260                                             Sodium, mg/100 g                                                                              370-650   370-520                                             Potassium, mg/100 g                                                                           180-600   180-470                                             Magnesium, mg/100 g                                                                           270-550   270-400                                             Phosphorus, mg/100 g                                                                          900-1500   900-1200                                           Chloride, mg/100 g                                                                            1400-2500 1400-2250                                           Iron, mg/100 g  13-25     13-20                                               Zinc, mg/100 g  3-6       3-6                                                 Manganese, mg/100 g                                                                           4-8       5-7                                                 Copper, mg/100 g                                                                              0.5-1.5   0.5-1.0                                             Vanadium, ppm   trace-15   8-12                                               Selenium, ppb   trace-350 150-300                                             Chromium, ppm   trace-2.9 1.5-2.3                                             Molybdenum, ppm trace-3.7 2-3                                                 ______________________________________                                    

                  TABLE 4                                                         ______________________________________                                        MOLECULAR                                                                     WEIGHT PARTITION FOR SPH (AS DETERMINED                                       BY SIZE EXCLUSION CHROMATOGRAPHY                                              OF SAMPLES FROM FOUR DIFFERENT LOTS OF SPH)                                             % of Particles                                                                With This Molecular Wt.                                             Molecular Wt.          Std.                                                   (in Daltons)                                                                              Average    Deviation Range                                        ______________________________________                                        >5000       3.3        1.96      1.70-5.96                                    2000-5000   25.8       5.42      19.50-30.75                                  1500-2000   20.5       7.41      13.10-27.50                                  1200-1500   12.5       0.92      11.80-13.80                                  1000-1200   8.2        0.83      7.30-9.00                                     500-1000   19.5       3.02      16.80-23.80                                  <500        10.2       6.03       5.30-19.00                                  ______________________________________                                    

Preferably, the soy protein hydrolysate used in the practice of thepresent invention has a molecular weight profile as determined by sizeexclusion chromatography wherein 30-60% of the particles have amolecular weight in the range of 1500-5000 Daltons. The use of soyprotein hydrolysate having other molecular weight profiles did notresult in acceptable products.

It was discovered that the soy protein hydrolysate used in thenutritional product of the present invention does not yield a shelfstable product in the absence of intact protein. Once a protein ishydrolyzed, it looses its primary and secondary structure andconsequently some of its functionality, including emulsifyingproperties. Therefore, it does not have surfactant properties and isunable to stabilize the formulation resulting in phase separation.Various approaches were investigated to attempt to stabilize a liquidproduct containing this particular soy protein hydrolysate.

Three different emulsifiers, and combinations thereof, were evaluated,but the most effective emulsifier is Panodan® which is distributed byGrinstead of Danisco, Denmark. Panodan® is diacetyl tartaric acid estersof mono-diglycerides and is an anionic surfactant with a veryhydrophilic component attached. Panodan® is generally regarded as safe(GRAS) for use in nutritional products for human consumption. Panodan®works by imparting a negative charge to the fat globules in thenutritional product, thus, causing them to electrostatically repel eachother so that no flocculation or coalescence occurs. The soy proteinhydrolysate could stay in an emulsion for about two weeks with Panodan®,but no other protein source present. It is, however, believed thatsodium stearoyl lactylate could also be used as an emulsifier, but thisemulsifier has not yet been classified as GRAS by the U.S. Food and DrugAdministration.

The use of starches to stabilize an emulsion containing the soy proteinhydrolysate was investigated, but this approach was abandoned becausethe viscosity of the emulsion was too high.

The use of intact proteins as a stabilizer was also investigated. Thestabilizing power of proteins has long been recognized. Caseinates, forexample, have a high electrical charge that make them hydrophilic andhave several hydrophobic groups. This, and their random coiled molecularstructure, makes them ideal emulsifiers with a strong preference forfat/water interfaces. It was discovered that a protein systemcomprising, by weight, at least 10-30% sodium caseinate with theremainder being the soy protein hydrolysate described herein, incombination with Panodan® yielded an emulsion having satisfactorystability with regards to phase separation.

The protein system in a preferred embodiment of the new enteralnutritional product comprises, by weight, about 78% soy proteinhydrolysate and about 22% sodium caseinate.

It is to be understood that the component(s) of the protein system of anutritional product of the present invention comprising intact proteincould comprise any suitable source of intact protein, such as peaprotein and whey protein concentrate, whether in place of or in additionto the sodium caseinate. For example, if it were desired to reduce thepH of the nutritional product to a more acidic level, at which sodiumcaseinate is not stable, then a source of intact protein such as a wheyprotein concentrate or isolate could be substituted for the sodiumcaseinate in an appropriate quantity.

A typical Amino Acid profile (mean of five batches of the nutritionalproduct of the present invention) is presented in TABLE 5.

                  TABLE 5                                                         ______________________________________                                        AMINO ACID PROFILE OF NUTRITIONAL PRODUCT                                     Amino       mg/g      mg/                                                     Acid        Protein   Liter     Range                                         ______________________________________                                        Histidine   26.1      1566.0    25.2-26.5                                     Isoleucine  38.7      2322.0    36.8-41.1                                     Leucine     70.8      4248.0    68.9-72.3                                     Lysine      68.6      4116.0    67.3-69.7                                     Methionine  14.8      888.0     13.6-16.3                                     Phenylalanine                                                                             42.8      2568.0    42.1-43.6                                     Threonine   39.7      2382.0    38.4-40.6                                     Tryptophan  6.5       390.0     6.0-7.1                                       Valine      40.9      2454.0    38.4-43.5                                     Phe + Tyr   78.2      4692.0    76.9-79.4                                     Met + Cystine                                                                             28.9      1734.0    27.2-30.2                                     Alanine     36.9      2214.0    36.1-37.7                                     Arginine    68.6      4116.0    67.1-70.1                                     Aspartic Ac.                                                                              115.1     6906.0    111.2-118.0                                   Cystine     14.1      846.0     13.0-14.5                                     Glutamic Ac.                                                                              216.7     13002.0   207.3-221.0                                   Glycine     36.0      2160.0    35.0-37.0                                     Proline     70.5      4230.0    66.8-72.3                                     Serine      54.2      3252.0    52.8-56.1                                     Tyrosine    35.4      2124.0    34.7-35.8                                     ______________________________________                                    

One of the problems encountered by persons infected with HIV isdiarrhea. The nutritional product of the present invention providesnutritional support to combat HIV inflicted diarrhea. Dietary fiber, inthe form of soy polysaccharides, adds bulk to the stool and helps toincrease water retention. As used herein and in the claims "dietaryfiber", or "fiber" is understood to refer to plant material that isundigested by human enzymes. Fiber may be partially digested by bacteriain the ileocecal region and in the colon, resulting in the production ofshort-chain fatty acids (acetate, propionate and butyrate) and gases(methane and carbon dioxide). Fiber is known to be beneficial inregulating bowel function in diarrhea. Soy polysaccharide, the source ofdietary fiber in the nutritional product of the present invention hasbeen shown to produce short-chain fatty acids in the intestine. Thenutritional product of the present invention contains about 8.9-11.6g/L, preferably about 8.9 g/1 (2.1 g/8 fluid ounces) of dietary fiberfrom soy polysaccharide.

The fat system is the nutritional product of the present inventionconsists, by weight, of about 70% canola oil; about 20% medium chaintriglycerides (MCT) oil (e.g. fractionated coconut oil); and about 10%fish oil. The emulsifiers used in the nutritional product of the presentinvention are diacetyl tartaric acid esters of mono-diglycerides. Theyconstitute about 5% of the oil blend. The fatty acid profile of thenutritional product is presented in TABLE 6.

                  TABLE 6                                                         ______________________________________                                        FATTY ACID PROFILE OF NUTRITIONAL PRODUCT                                                           % OF TOTAL                                                                    FATTY ACIDS                                             FATTY ACID            BY WEIGHT                                               ______________________________________                                        Caprylic (8:0)          10-14.5                                               Capric (10:0)           5-8.5                                                 Lauric (12:0)         about 0.08                                              Myristic (14:0)       0.58-0.70                                               Palmitic (16:0)       4.3-5.7                                                 Palmitoleic (16:1 n-7)                                                                              0.9-1.1                                                 Stearic (18:0)        3.5-5.0                                                 Oleic (18:1 n-9)      41.0-42.0                                               Linoleic (18:2 n-6)   13.8-17.1                                               Alpha-Linolenic (18:3 n-3)                                                                          5.6-6.4                                                 Stearidonic (18:4 n-3)                                                                              about 0.3                                               Eicosanoic (20:1 n-9) 1.1-1.2                                                 Eicosapentaenoic (20:5 n-3) (EPA)                                                                   2.4-3.4                                                 Behenic (22:0)        0.2-0.4                                                 Erucic (22:5 n-3)     0.3-0.4                                                 Docosapentaenoic (22:1 n-9)                                                                         about 0.2                                               Docosahexaenoic (22:6 n-3) (DHA)                                                                    1.3-1.4                                                 Nervonic (24:1 n-9)   0.0-0.1                                                 Others                0.4-1.1                                                 Polyunsaturated Fatty Acids                                                                         about 26%                                               Saturated Fatty Acids about 29%                                               Ratio of Polyunsaturated to Saturated                                                                about 0.9%                                             Ratio of total n-6 to total n-3 fatty                                                               1.3:1-2.5:1                                              acids                                                                        ______________________________________                                    

The refined deodorized fish oil used in the nutritional product of thepresent invention contains about 45% total n-3 polyunsaturated fattyacids, of which about 28% are Eicosapentanoic acid (EPA, C20:5n-3) and13% are Docosahexanoic acid (DHA, C22:6n-3). These unsaturated fattyacids make the oil very prone to oxidation. Thus, approximately 7000 ppmof natural mixed tocopherols are added to the oil by the supplier beforeshipment to prevent oxidation. Upon arrival the oil is kept undernitrogen and refrigeration until it is used. The shelf-life assigned tothis commodity is only 70 days to assure that the oil is of optimalquality at the time of use. The nutritional product has beenmanufactured using a fish oil manufactured from sardines and has beenobtained from Mochida International in Shijuku-Ku, Tokyo, Japan.

Although there is no specific dietary requirement for total fat, some isneeded to provide essential fatty acids, to carry fat-soluble vitamins,and to facilitate their absorption. N-3 fatty acids, for example fromfish oil, reduce prostaglandin production and the expression of certainoncogenes, e.g. RAS. N-3 fatty acids also reduce the expression ofapoptotic genes (cell death genes). The liquid nutritional product ofthe present invention contains not less than 1900 mg of n-3 fatty acidsper liter (450 mg per 8 fluid ounces). The ratio, by weight, of the sumof the n-6 fatty acids to the sum of the n-3 fatty acids in thenutritional product is about 1.3:1 to 2:5 to 1, preferably about 1.5:1.

The fatty acid profile of the nutritional product of the presentinvention meets the recommendation of the American Heart Association forless than 10% of calories from saturated fat and not more than 10% ofcalories from polyunsaturated fat.

The carbohydrate system in the nutritional product of the presentinvention consists of a mixture of complex carbohydrates and simplesugars which are provided by the following product ingredients in thefollowing proportions, by weight: about 72.1% hydrolyzed cornstarch;about 22.8% sucrose; and about 5.1% soy polysaccharide.

The stabilizer used in the nutritional product of the present inventionis a mixture of Kappa and Iota carrageenan at 350 ppm level. Carrageenanis a high molecular weight linear polysaccharide obtained from redseaweed plants.

The nutritional product of the present invention provides at least 100%of the US RDA for vitamins and minerals in 1184 ml (five 8 fluid ounceservings). The oil soluble vitamins (Alpha-tocopheryl acetate, vitamin Apalmitate, Phylloquinone, Vitamin D3) are added as a premix. The watersoluble vitamins (Niacinamide, d-calcium pantothenate, Thiaminehydrochloride, Pyridoxine hydrochloride, Riboflavin, Folic acid, Biotin,Cyanocobalamin) are also added as a premix. Beta Carotene is added as a30% solution in vegetable oil. Choline chloride, Taurine, L-Carnitine,Ascorbic acid and additional Cyanocobalamin are added individually.

The soy protein hydrolysate in the formulation provides 100% of thechromium and molybdenum needed. The remaining minerals come from sodiumcitrate, calcium carbonate, ultramicronized tricalcium phosphate (TCP),magnesium phosphate dibasic, copper sulfate, sodium selenate, zincsulfate, manganous sulfate, ferrous sulfate and potassium iodide. It hasbeen observed that additional TCP may need to be used if the level ofphytate in the soy protein hydrolysate is so high that it renders toomuch of the phosphorus from the SPH biologically unavailable.

The concentrated levels of vitamins and minerals, which are presented inTABLE 1, enable the nutritional product of the present invention to meetthe nutritional requirements of enterally fed patients with a smallervolume of the product. HIV infected patients often need volumerestriction because of gastrointestinal tract problems, or drug-ortreatment-related anorexia, nausea, and/or vomiting.

The nutritional product of the present invention contains β-carotene, acarotenoid compound that has pro-vitamin A activity. However, unlikevitamin A, β-carotene is not associated with toxicity and, therefore,may be used as a source of retinol equivalents in the diet withoutintroducing toxicity concerns. Vitamin A has been shown to reverse someof the immunosuppression associated with thermal injury and radiationinjury.

The levels of vitamins E and C, folic acid, and vitamin B₁₂ provided by1184 mL (five 8 fluid ounce servings) per day of the nutritional productof the present invention greatly exceed the US RDA's for these nutrientsin order to encourage adequate storage in the early phases of thedisease and to attempt to counteract the deficiencies in these vitaminsobserved in the later stages. The minerals iron, magnesium, zinc andselenium have been included at levels intended to counteract depletionor deficiencies of these nutrients which have been observed as thedisease progresses.

Another problem encountered by persons infected with HIV is cachexia(weight loss). N-3 fatty acids provided, for example, by fish oil andcanola oil, significantly stay cachexia by inhibiting cachectins andtumor necrosis factor, which are involved in metabolic changes. Thecachectins reduce an individual's ability to maintain lean body mass inthe face of increased lipogenesis (exchanging lean muscle for fat). Thehigh caloric density of the nutritional product of the presentinvention, as well as the enterotrophic peptides from the soy proteinhydrolysate, provides a source of high nitrogen to maintain proteinsynthesis. The nutritional product of the present invention has a verylow calorie: nitrogen ratio of about 135:1. The above indicated benefitshave been indicated in HIV infected persons fed the nutritional productof the present invention by evaluating body composition (% lean bodymass and body fat), intermediary metabolism using stable isotopes, andmeasuring cytocines.

Another problem encountered by persons infected with HIV is thedepletion of specific nutrients, such as selenium, magnesium, zinc,vitamin B₆, vitamin B₁₂, folate, and beta carotene. As indicated inTABLE 1, the nutritional product of the present invention provides thesenutrients in amounts which far exceed the U.S. RDA for these nutrients.

Another problem encountered by persons infected with HIV is an increasedrisk of cardiomyopathy. The nutritional product of the present inventioncontains nutrients which reduce the risk of cardiomyopathy. Theseingredients include selenium, fish oil, β-carotene and vitamin E.

Appropriate amounts of electrolytes (sodium, potassium and chlorides)are required for the maintenance of fluid status and other importantfunctions such as the synthesis of protein. Potassium, in particular, isimportant because, for example, catabolic patients lose potassium inurine when nitrogen is lost from muscle. Likewise, anabolic patientsretain more potassium as more nitrogen is incorporated into muscletissue during recovery. Sodium and potassium in the nutritional productof the present invention are supplied by the SPH, sodium citrate, sodiumchloride and potassium hydroxide. One hundred percent of the chloriderequirement is provided by the SPH. The nitrogen/potassium ratio of thenutritional product of the present invention is about 3.5:1, which isbelieved will provide for some repletion of potassium lost with HIVrelated conditions such as vomiting and diarrhea. The electrolytecontent of the nutritional product varies between flavors, but isgenerally in the following ranges: sodium, about 970 to 1050 mg perliter (230 to 249 mg per 8 fluid oz); potassium, about 2600 to 2830 mgper liter (620 to 670 mg per 8 fluid oz); and chloride, about 1400 to1550 mg per liter (340 to 370 mg per 8 fluid oz).

The major determinants of the osmolality of a nutritional product aresimple carbohydrates, electrolytes, and amino acids or small peptides.Because the nutritional product of the present invention is formulatedwith a specific soy protein hydrolysate providing a high content ofpeptides and with elevated potassium levels to provide metabolic andphysiologic advantages to the HIV infected patient, its osmolality ishigher than isotonic. The osmolality of the nutritional product of thepresent invention is about 660 mosm/kg water.

The nutritional product of the present invention has a viscosity ofabout 24-45 cps and has been formulated for use both as an oralsupplement and for total enteral support, either orally or by tubefeeding. The density of the nutritional product at 23° C. is about 1.105g/ml, and the pH of the nutritional product is about 6.4 to 6.6.

Two flavor systems have been developed for the new nutritional product:chocolate and orange cream. For the chocolate product, the amount ofcaffeine provided by the cocoa powder is approximately 8.38 mg per 8 fl.oz. or 41.9 mg per nutrient base. The level of theobromine is 52.4 mgper 8 fl. oz. or 262 mg per 1184 mL.

The process of manufacturing a nutritional formula for HIV/AIDS patientsaccording to the present invention begins with the preparation of an oilblend containing the oils, emulsifier and oil soluble vitamins. Two moreslurries (carbohydrate slurry and protein/mineral slurry) are preparedand mixed together with the oil blend to which a portion of the proteinhas been added. The resulting mixture is homogenized, heat processed,standardized with vitamins and minerals, flavored, and terminallysterilized. TABLES 7 and 8 are the bills of materials used in themanufacture of 1,000 kg batches of orange cream and chocolate products,respectively, according to the present invention.

                  TABLE 7                                                         ______________________________________                                        BILL OF MATERIALS                                                             FOR ORANGE CREAM FLAVOR PRODUCT                                                                         AMOUNT                                                                        PER 1,000                                           COMPONENT                 kg (in kg)                                          ______________________________________                                        Canola Oil                    15.10                                           MCT Oil (fractionated coconut oil)                                                                          4.31                                            Diacetyl Tartaric Acid Esters of                                                                            1.11                                            Mono and Diglycerides (Panodan ®)                                         Oil Soluble Vitamins Premix   0.0585                                           Alpha-tocopheryl Acetate                                                                         0.04299                                                    Vitamin A Palmitate                                                                               0.003574                                                  Phylloquinone       0.000079                                                  Vitamin D3          0.0000097                                                 Coconut Oil (carrier)                                                                            Q.S.                                                      Beta Carotene                 0.0188                                          Sodium Caseinate              13.34                                           Water                         701.63                                          Sucrose                       43.12                                           Corn Syrup Solids             136.18                                          Sodium Citrate                1.47                                            Magnesium Phosphate dibasic   0.7469                                          Tricalcium Phosphate (preferably ul-                                                                        0.0893                                           tra micronized)                                                              Calcium Carbonate             1.62                                            Soy protein Hydrolysate       52.87                                           45% KOH (proc. Aid)           6.19                                            Soy Polysaccharides           10.43                                           Iota Carrageenan              0.3                                             Kappa Carrageenan             0.05                                            Fish Oil high omega 3         2.16                                            Ferrous Sulfate               0.03476                                         Manganous Sulfate             0.0062                                          Copper Sulfate                0.0098                                          Sodium Selenate               0.00014                                         Zinc Sulfate                  0.07035                                         Water Soluble Vitamin Premix  0.0875                                           Niacinamide                  0.03286                                          d-Calcium Pantothenate                                                                           0.02126                                                    Pyridoxine Hydrochloride                                                                         0.00522                                                    Thiamine Hydrochloride                                                                           0.00543                                                    Riboflavin         0.00424                                                    Folic Acid         0.00074                                                    Biotin             0.00064                                                    Cyanocobalamin      0.000014                                                  Dextrose (carrier) Q.S.                                                      Taurine                       0.210                                           L-Carnitine                   0.1460                                          Potassium Iodide              0.000158                                        Choline Chloride              0.2660                                          Cyanocobalamin                0.00007                                         Ascorbic Acid                 0.7240                                          Orange Cream Flavor           4.00                                            Artificial Fresh Cream        3.5                                             ______________________________________                                    

                  TABLE 8                                                         ______________________________________                                        BILL OF MATERIALS                                                             FOR FORMULA CHOCOLATE FLAVOR PRODUCT                                                                    AMOUNT                                                                        PER 1,000                                           COMPONENT                 kg (in kg)                                          ______________________________________                                        Canola Oil                    14.5                                            MCT Oil                       4.14                                            Diacetyl Tartaric Acid Esters of                                                                            1.07                                            Mono and Diglycerides (Panodan ®)                                         Oil Soluble Vitamins Premix   0.0585                                           Alpha-tocopheryl Acetate                                                                         0.04299                                                    Vitamin A Palmitate                                                                              0.003574                                                   Phylloquinone      0.000079                                                   Vitamin D3          0.0000097                                                Coconut Oil (carrier)                                                                             Q.S.                                                      β-Carotene               0.0188                                          Sodium Caseinate              13.34                                           Water                         703.72                                          Sucrose                       42.27                                           Corn Syrup Solids             133.49                                          Sodium Citrate                1.47                                            Magnesium Phosphate dibasic   0.461                                           Tricalcium Phosphate (preferably ul-                                                                        0.060                                            tramicronized)                                                               Calcium Carbonate             1.61                                            Soy protein Hydrolysate       54.87                                           45% KOH (proc. Aid)           5.17                                            Soy Polysaccharides           9.92                                            Iota Carrageenan              0.3                                             Kappa Carrageenan             0.05                                            Cocoa Powder                  8.0                                             Fish Oil high omega 3         2.07                                            Ferrous Sulfate               0.03476                                         Manganous Sulfate             0.0062                                          Copper Sulfate                0.0098                                          Sodium Selenate               0.00014                                         Zinc Sulfate                  0.07035                                         Water Soluble Vitamin Premix  0.0875                                           Niacinamide        0.03286                                                    d-Calcium Pantothenate       0.02126                                          Pyridoxine Hydrochloride                                                                         0.00522                                                    Thiamine Hydrochloride                                                                           0.00543                                                    Riboflavin         0.00424                                                    Folic Acid         0.00074                                                    Biotin             0.00064                                                    Cyanocobalamin      0.000014                                                  Dextrose (carrier) Q.S.                                                      Taurine                       0.1946                                          L-Carnitine                   0.146                                           Potassium Iodide              0.000158                                        Choline Chloride              0.266                                           Cyanocobalamin                0.00007                                         Ascorbic Acid                 0.724                                           Artificial Chocolate Flavor   1.4                                             Artificial Fresh Cream        3.5                                             ______________________________________                                    

An oil blend is prepared by adding the required amount of canola oil andMCT oil to a blend tank and heating the oils to a temperature of about57°-68° C. (135°-155° F.) with agitation. The required quantity of thePanodan® emulsifier, (diacetyl tartaric acid esters of mono anddiglycerides), is added to the heated oil blend. The oil solublevitamins premix and beta carotene are then added and mixed well toinsure proper blending.

A protein-in-fat slurry is prepared by adding to the oil blend one halfof the sodium caseinate while agitation is maintained. This slurry iskept at a temperature of about 40°-46° C. (105°-115° F.) until use.

A carbohydrate slurry is prepared by weighing the appropriate amount ofwater in a suitable tank and heating the water to a temperature of about68°-74° C. (155°-165° F.). Sucrose and corn syrup solids are added underagitation to make a 60% solution, by weight.

A mineral/protein slurry is prepared by weighing the appropriate amountof water and heating the water to a temperature of about 68°-74° C.(155°-165° F.). The following ingredients are dissolved/suspended in thewater with agitation in the following order: sodium citrate, magnesiumphosphate dibasic, tricalcium phosphate, calcium carbonate, soy proteinhydrolysate and mixed well until it is completely dissolved, to yield a27% slurry by weight. The pH of the mineral/protein slurry is thenadjusted to about 5.7-6.0 with 45% KOH.

A blend is prepared by heating the appropriate amount of water to atemperature of about 57°-68° C. (135°-150° F.) and adding the remainingsodium caseinate, soy polysaccharides, iota carrageenan and kappacarrageenan. For chocolate flavored batches, the needed amount of cocoapowder is then added and mixed well to insure homogeneity. A mixingapparatus such as the two stage blender which is described in U.S. Pat.No. 4,850,704, which is incorporated herein for the purpose of teachingappropriate equipment for practicing the invention, may be used inmaking this blend.

The carbohydrate slurry, the mineral/protein slurry and theprotein-in-fat slurry are combined together with agitation to yield ablend having 34% solids, by weight. The pH of the blend should be in therange of 6.25-6.55. If an adjustment of pH is needed, 1N KOH or 1Ncitric acid are added. Prior to emulsification fish oil is metered intothe blend at a constant rate such that the dispersion of fish oil isuniform throughout the blend.

The blend is emulsified, ultra-high temperature processed (299°-304°F.), then homogenized at 3900-4100/500±100 psig using 2 stagehomogenizer. The processed blend is then cooled to 1°-7° C. (34°-45°F.).

A solution of vitamins, amino acids and minerals containing about 9.0%solids by weight, is prepared by heating the appropriate amount ofdefluoridized water to a temperature of about 43°-54° C. (110°-130° F.).The minerals are then added with agitation, preferably in the followingorder: ferrous sulfate, manganous sulfate, copper sulfate, sodiumselenate and zinc sulfate and potassium iodide. The vitamins and aminoacids are added with agitation in the following order: water solublevitamin premix, taurine, L-carnitine, choline chloride, andcyanocobalamin. The solution of vitamins and minerals is then added tothe blend, with agitation.

An ascorbic acid solution, 12% solids, is prepared by combining therequired amount of 45% KOH with cold ingredient water and adding therequired amount of ascorbic acid. Once the pH is determined to be in therange of 6-10, the ascorbic acid solution is added, with agitation, tothe blend.

For the orange cream flavor, the flavor solution is prepared bycombining the necessary amount of water, at a temperature of about38°-49° C. (100°-120 F.), with the orange cream flavor. The artificialfresh cream is then added. For the chocolate flavor product, the flavorsolution is prepared by mixing the necessary amount of water, at atemperature of about 38°-49° C. (100°-120° F.), the artificial chocolateflavor, and the artificial fresh cream. In each instance the flavorsolution contains about 20% solids. The flavor solution is added, withagitation, to the blend.

The pH of the complete blend is adjusted to 6.6-6.8 with 1N KOH or 1Ncitric acid, placed in suitable container, such as 8 oz. metal cans, andterminally sterilized. Of course, if desired, the nutritional productmay be manufactured using aseptic methods, and packaged in suitablecontainers.

The nutritional product manufactured by the method described herein is aready-to-serve liquid which can be consumed orally or be tube-fed. Whilethe nutritional product of the present invention has only beenmanufactured in a ready-to-feed liquid form, it is understood that itmay be produced in a concentrated liquid form for later dilution or inpowder form for later reconstitution with a suitable liquid withoutdeviating from the scope of the present invention.

A study has been conducted with the enteral nutritional product of thepresent invention. This study was designed to assess the relativeeffects of the nutritional product of the present invention as comparedto a standard enteral whole protein-based formula, Ensure® on numerousprognostic markers of nutritional, immune, and gastrointestinal statusand function in HIV infected and AIDS patients. Ensure® is distributedcommercially by Ross Laboratories, a Division of Abbott Laboratories,Columbus, OH, U.S.A. A comparison of these two products is presented inTABLE 9.

Upon entrance into the study, patients were randomly assigned to eitherthe group fed the product of the present invention (n=17) or the control(Ensure®) group (n=22), and instructed to consume at least 16 oz. of therespective enteral nutritional product per day as supplement to theirnormal routine intake for an initial period lasting 6 weeks. Totaldietary intake (supplement plus other food consumed) was monitoredthroughout the study using serial 7-day food intake records and revealedno significant differences in overall intake of protein, fat orcarbohydrate between the two groups. Baseline assessment of age, height,weight, and weight loss also revealed no significant differences betweenthe two groups. Baseline and follow-up (at 6 weeks) blood samples wereobtained in the fasting state and used for the measurement ofbiochemical indicators of nutritional and immune status. In addition,detailed assessment of body compositional changes (anthropometrics andbioelectrical impedance) and of clinical outcome variables including,but not limited to, bowel habits, Karnofsky performance score,hospitalizations, medication usage, and cardiac performance, wereobtained at both baseline and at the six week follow-up. In order toassess gastrointestinal integrity and function, as well as the relativeenterotrophic effects of the respective enteral supplements on theseparameters, duodenal biopsies were obtained at both baseline and atfollow-up in a subset population (new product, n=6; Ensure®, n=5) fromthis study, and biopsy samples were evaluated for histological andmorphometric parameters via transmission electron microscopy.

From the population of HIV infected and AIDS patients being followed ata major medical center, 39 patients with HIV infection includingpatients diagnosed with ARC and AIDS were studied over a 6 week period.Subjects ranged from 13 to 60 years of age. Subjects were entered intothe study without regard to sex or race. Patient eligibility criteriaincluded individuals with confirmed HIV infection, a favorable Karnofskyperformance status (65-100) and adequate hematologic (WBC greater than200/ mm2, platelets greater than 100,000), renal (serum creatinine lessthan 2 mg/dl) and hepatic (bilirubin less than 2 mg/dl) functions. Inaddition, patients who had lost more than 30% of their ideal body weightwere excluded from entry into the study. All data and samples fromindividuals participating in this study were collected respectively inconjunction with nutrition data collection visits. This was adouble-blinded prospective study.

The results indicated that the enteral nutritional product disclosedherein significantly supports immune function, GI symptomology, physicalperformance, and positive trends in body composition when contrastedwith a standard enteral feeding (Ensure®)over the treatment period.These results provide significant data for support of the efficacy ofthe product disclosed herein in the HIV/AIDS patient.

                  TABLE 9                                                         ______________________________________                                        NUTRIENT PROFILES OF CONTROL (ENSURE ®) NU-                               TRITIONAL PRODUCT OF THE PRESENT INVENTION                                    (ANALYSIS OF PRODUCTS USED IN STUDY)                                          NUTRIENT                                                                      (per 8 fl. oz)                                                                              ENSURE ®                                                                              NEW PRODUCT                                         ______________________________________                                        Energy, kcal. 250         303                                                 Protein, g    8.8         14.2                                                Carbohydrate, g                                                                             34.3        51.1                                                Fat, g        8.8         5.4                                                 B-carotene, (mg)                                                                            --          1.2                                                 Vitamin A, IU 625         1000                                                Vitamin D, IU 50          80                                                  Vitamin E. IU 5.6         9.0                                                 Vitamin K, mcg                                                                              9           16                                                  Vitamin C, mg 37.5        90.0                                                Folic acid, mcg                                                                             100         120                                                 Thiamine, mg  0.38        0.75                                                Riboflavin, mg                                                                              0.43        0.68                                                Vitamin B-6, mg                                                                             0.5         0.8                                                 Vitamin B-12, mcg                                                                           1.5         12.0                                                Niacin, mg    5.0         6.0                                                 Choline, mg   75          50                                                  Biotin, mcg   75          90                                                  Pantothenic acid, mg                                                                        2.5         3.0                                                 Sodium, mg    200         240                                                 Potassium, mg 370         620                                                 Chloride, mg  310         350                                                 Calcium, mg   125         200                                                 Phosphorus, mg                                                                              125         200                                                 Magnesium, mg 50          80                                                  Iodine, mcg   18.8        30.0                                                Manganese, mg 0.62        1.25                                                Copper, mg    0.25        0.60                                                Zinc, mg      2.82        3.75                                                Iron, mg      2.25        4.50                                                Selenium, mcg --          14                                                  Chromium, mcg --          20                                                  Molybdenum, mcg                                                                             --          30                                                  L-carnitine, mg                                                                             --          30                                                  Taurine, mg   --          50                                                  ______________________________________                                    

TABLE 10 presents a concise summary of the more significant changeswhich were observed in this six week supplement protocol. The arrows andtheir respective statistical significance are indicated for thecomparison of follow-up to baseline (change from baseline) for both thecontrol and new product groups. An overall review of the variablesindicated in TABLE 10 reveal that many, if not most of the parameters,either are significantly different or are approaching statisticalsignificance in the control group, while most of the parameters in thenew product group are maintained or do not change.

                  TABLE 10                                                        ______________________________________                                        SUMMARY OF CLINICALLY SIGNIFICANT RESULTS                                                     (WEEK 0    (WEEK 0                                                            vs 6)      vs 6)                                              ______________________________________                                        PARAMETER       CONTROL    NEW PRODUCT                                        WBC             ↑ NS -- NS                                              (×10.sup.3 cells/mm.sup.3)                                                              (p = 0.2136)                                                                             (p = 0.8409)                                       LYMPHOCYTES     ↓   -- NS                                              (%)             (P = 0.0003)                                                                             (P = 0.8502)                                       NEUTROPHILS     ↑    -- NS                                              (%)             (P = 0.0055)                                                                             (p = 0.7255)                                       IGA             ↑    ↑                                            (mg/dL)         (p = 0.0370)                                                                             (p = 0.0309)                                       TOTAL LYMPHOCYTES                                                                             ↓ TREND                                                                           -- NS                                              (×10.sup.3 cells/mm.sup.3)                                                              (p = 0.0581)                                                                             (p = 0.9570)                                       CD4             ↓ TREND                                                                           -- NS                                              (cells/mm.sup.3)                                                                              (p = 0.0663)                                                                             (p = 0.3373)                                       CD8             ↓ TREND                                                                           ↑ NS                                         (cells/mm.sup.3)                                                                              (p = 0.0756)                                                                             (p = 0.9341)                                       CD4/CD8 Ratio   ↓ NS                                                                              ↓ NS                                                        (p = 0.7096)                                                                             (p = 0.8512)                                       CD4/Albumin Ratio                                                                             ↓   ↓ NS                                                        (p = 0.0483)                                                                             (p = 0.4887)                                       BOWEL HABITS    ↓ TREND                                                                           ↓ TREND                                     (AVG # )        (p = 0.1060)                                                                             (p = 0.0869)                                       KARNOFSKY SCORE ↓ NS                                                                              -- NS                                                              (p = 0.5781)                                                                             (p = 1.000)                                        BUN             ↑    -- NS                                              (mg/dL          (p = 0.0324)                                                                             (p = 0.4836)                                       CREATININE      -- NS      ↑ TREND                                      (mg/dL)         (p = 0.3489)                                                                             (p = 0.0781)                                       ______________________________________                                         Note:                                                                         (a) In this Table if "p" is greater than 0.05 the result is not               significant; if "p" is equal to or less than 0.05 the result is highly        significant; and if "p" is equal to or less than 0.12 the result shows a      strong trend.                                                                 (b) In this Table "NS" means not significant.                            

Total lymphocytes in the group fed the nutritional product of thepresent invention increased, while they fell in the control group. CD8lymphocytes increased in the group fed the nutritional product of thepresent invention (NS), and again fell in the control group. Conversely,CD4 cell counts showed a strong trend in the control group, but wereunchanged in the new product group. In contrast, CD4:CD8 ratios whichdecrease with AIDS progression, decreased to a greater extent in thecontrol group as compared to the new product group. In addition toenhanced or maintained function in the new product group, this groupexperienced a reduction in GI symptomology, significant trends in bodycomposition maintenance, maintenance of physical performance, improvedcardiac function as measured by increased respiratory sinus arrhythmiaamplitude, and significant GI tolerance, but the specific efficacy ofthe nutritional product of the present invention is where such efficacymay possibly be linked to reduced immune cell death (apoptosis).

White blood cell count (WBC) was increased in the control group while nochange was apparent in the new product group. Although not statisticallydifferent, WBC increased from 3.2±0.3 to 4.4±0.7 cells×10³ /mm³ in thecontrol group. This increase in WBC in the control group was apparentlydue to a significantly elevated neutrophil count in the control groupafter six weeks of supplement use. In addition to the elevation inneutrophil count, the percent of white blood cells due to lymphocyteswas reduced in the control group after six weeks of the supplement use.There was no change in percent lymphocytes between baseline andfollow-up in the new product group. These changes in WBC and certain ofits respective components indirectly suggest that the control group wasmore immunocompromised than the new product group at follow-up (aftersix weeks of supplement use).

None of the parameters presented demonstrated any significant differencebetween the two groups at baseline, indicating the similar immune statusof all patients upon entry into the study. However, as discussed abovein the assessment of white blood cell count and its respectiveconstituents, total lymphocyte count was significantly decreased in thecontrol group after six weeks of the supplementation. Although notstatistically significant, the mean absolute number of total lymphocytesdecreased in the control group while it increased in the new productgroup after six weeks of supplementation. In addition, both CD4 and CD8levels, excellent prognostic markers of AIDS progression, decreased inthe control group after six weeks of supplementation. Conversely, CD4levels in the new product group were maintained at baseline levels andCD8 levels actually increased after six weeks of supplementation. Thereappears to be a definitive trend in these markers of AIDS progressionsuggesting that the patients fed the new product were better able tomaintain immunocompetence throughout the course of the study as comparedto the controls. Further evidence of this maintained immune status ispresented in TABLE 10. Both CD4/CD8 and CD4/albumin ratios decreased toa much greater degree in the control group (23% and 15%, respectively ascompared to the new product group (4% and 6%, respectively). Once again,although not statistically significant in all cases, these results areclearly indicative of a trend and further confirm the observation thatthe patients fed the new product were better able to maintain theirimmune status as compared to the controls. Additional support for thiscontention comes from the results presented in TABLE 11. This tablepresents an assessment of the number of patients in both groups thatprogressed to CD4 levels below 150 after six weeks of supplementation.The results clearly demonstrate that supplementation with the newproduct is able to prevent the fall of CD4 to a level below 150 in alarger proportion of patients than the control supplement.

                  TABLE 11                                                        ______________________________________                                                     CONTROL  NEW                                                                  GROUP    PRODUCT GROUP                                           ______________________________________                                        CD4% Change 1.5 mo.                                                                          -19%       NC (No Change)                                      CD4% Change 1.5 mos.                                                                         -43%       +14%                                                Patient with CD4 > 150                                                        CD4% Change 1.5 mos.                                                                         +23%       -20%                                                Patients with CD4 < 150                                                       ______________________________________                                    

Apoptosis, also referred to as programmed cell death, is an active cellsuicide process that depends on the environment, in particular on thenature and intensity of activation signals received by cells. Apoptosisinvolves chromatic condensation, membrane blebbing and fragmentation ofDNA, all of which are clearly visible upon microscopic examination. Onthe other hand, cell death due to necrosis, caused, for example, bytrauma or disease, has results which are clearly distinguishable fromapoptotic cells upon microscopic examination. Apoptosis of CD4 cells inboth HIV positive and AIDS patients has been reported in reputablescientific publications, for example: Gougeon, "Apoptosis as a Mechanismof Cell Death in Peripheral Lymphocytes from HIV-1-InfectedIndividuals", IMMUNODEFICIENCY IN HIV INFECTION AND AIDS, pages 115-126(1992); and Ameisen, "THE PROGRAMMED CELL DEATH THEORY OF AIDSPATHOGENESIS: IMPLICATIONS, TESTABLE PREDICTIONS, AND CONFRONTATION WITHEXPERIMENTAL FINDINGS", IMMUNODEFICIENCY REVIEWS, Vol. 3, pages 237-246(1992). Since priming for apoptosis has been reported to occur early inthe course of the disease, any possible intervention should be initiatedearly in order to be most effective. While at the present time theeffect an intervention in the apoptosis of CD4 cells in HIV positive andAIDS patients may have on the further course of the disease, it hasknown that the depletion of CD4 cells leads to loss of immune functionswhich eventually results in the patient being subjected to opportunisticinfections. The data presented in TABLES 10 and 11, and the accompanyingremarks, clearly indicated that enteral nutritional support of a personinfected with human immunodeficiency virus with the nutritional productdisclosed herein impedes the apoptosis of CD4 cells. That is to say thisnutritional support does not absolutely eliminate apoptosis of CD4cells, but it appears that some component of the nutritional productinterferes with the transmission of signals to CD4 cells which initiateapoptosis. It is believed that the soy protein hydrolysate used in thenutritional product provides some agent, perhaps a peptide, whichresults in this beneficial biological effect. Enterally providing thissoy protein hydrolysate in a therapeutically effective quantity isbelieved to impede the apoptosis of CD4 cells in a person infected withimmunodeficiency virus.

In addition to the above assessments of immune status, immunoglobulinlevels for IgG, IgM, and IgA were also assessed at both baseline andafter six weeks of supplementation at follow-up. No statisticaldifferences were observed for each of these parameters at baseline whencontrol and new product supplemented patients were compared. However,after six weeks of supplementation, each immunoglobulin level hadincreased. IgG, although increased in both groups, were notsignificantly increased in either group. However, the increase in IgG inthe control group resulted in a mean value which was outside of theclinically normal range, while the increased mean value in the group fedthe new product remained within normal clinical ranges. As was the caseof IgG, IgM mean levels were also increased in both groups(statistically elevated in the group fed the new product). However, meanIgM levels in both groups remained within the normal clinical range. IgAwere statistically elevated in both the control and the group fed thenew product after six weeks.

TABLE 10 presents the change in the average number of bowel movementsper day for the control and new product groups. Interestingly, enteralsupplement appeared to decrease the mean number of bowel movements perday in both supplement groups. Although not statistically significant,the average number of bowel movements per day decreased by almost 1 perday in both groups after six weeks of supplementation. When the datafrom both groups were pooled together the average number of bowelmovements per day were significantly decreased at follow-up frombaseline. This is an interesting finding since enteral supplementationhas not commonly been shown to result in a decrease in average number ofbowel movements per day, but rather has been reported to be associatedwith an increase in this parameter. In addition to subjectivelyrecording the average number of bowel movements per day, patients alsoprovided detailed information with regard to stool consistency. Therewere no significant differences between the two study groups with regardto stool consistency either at baseline or after six weeks ofsupplementation. Furthermore, the respective nutritional supplementsappeared to have no effect on the change from baseline with regard tostool consistency.

Another important clinical outcome variable measured in this study wasthe Karnofsky score. The Karnofsky score provides a subjectiveassessment of quality of life made by a patient's personal physician.TABLE 10 presents the change in the Karnofsky scores for the control andnew product supplemented groups. At baseline, both study groups werenearly identical with regard to functional status (76 vs. 80 for thecontrol and new product group respectively). However, although notstatistically different, it is clear that the average Karnofsky scoresin the control group declined to a larger degree (21%) than those of thenew product group (9%) over the course of the six week study.

The only biochemistries which demonstrated clinically significantchanges were creatinine and blood urea nitrogen (BUN). Serum creatinine,although not statistically significant., increased from 1.0±0.1 to1.1±0.1 mg/dL in the new product group after six weeks of supplement usewhile no change was observed in the control group. Conversely, BUNsignificantly increased from 14 to 15 mg/dL in both the control and newproduct groups. This increase in BUN was only statistically significantin the control group. Together, these observations suggest that thepatients receiving the control supplement had a larger degree of proteinbreakdown as compared to the new product group and that the new productgroup was better able to increase muscle mass during the course of thestudy than the controls (as indirectly evidence by an increasedcreatinine level after six weeks of supplementation).

In an attempt to assess the enterotrophic effects of the new product andits constituent soy protein hydrolysate (SPH), fish oils, and solublefiber system, terminal duodenal biopsies were obtained in a subsetpopulation of patients enrolled in this study. Six control patients and7 patients fed the new product had baseline and six week follow-upbiopsies obtained via direct endoscopy. Biopsy samples were fixed inglutaraldehyde and processed for electron microscopic analysis. Nosignificant differences either between groups at baseline and follow-upor between change from baseline for the respective supplement groupswere observed for microvillus height, microvillus diameter andmicrovillus surface area.

Standard anthropometric variables and their respective calculated bodycomposition parameters were recorded. The data clearly demonstrate nosignificant differences or changes between any of these parameters forboth study groups. It should be noted, however, that although nosignificant improvements were observed, both supplements were able tomaintain individual anthropometric variables as well as bodycompartments including fat mass, fat-free mass, and percent body fat.Based on the fact that the patients enrolled in this study werereporting significant weight loss (10% from usual) upon entry into thestudy, this alone provides clear evidence that enteral supplementationcan reduce or prevent the progressive weight loss associated with theprogression of AIDS.

Another very important and costly consequence of HIV-infection and/orAIDS is the requirement of multiple hospitalizations. Five of the 22control group patients (23%) required at least one additionalhospitalization during the course of this six week study while none ofthe new product supplemented patients required an additionalhospitalization (p<0.5). The cost of a single hospitalization fortreatment of AIDS related complications is enormous. This findingtherefore warrants further investigation.

What is claimed is:
 1. A liquid nutritional product for enteralnutritional support of a person infected with human immunodeficiencyvirus comprising:(a) a first source of protein comprising a soy proteinhydrolysate having a molecular weight partition, as determined by sizeexclusion chromatography, wherein 30-60% of the particles have amolecular weight in the range of 1500-5000 Daltons; (b) a second sourceof protein which comprises a source of intact protein in a quantitysufficient to yield a stable emulsification of the soy proteinhydrolysate and the intact protein in the nutritional product; (c) anemulsifier selected from the group consisting of diacetyl tartaric acidesters of mono-diglycerides and sodium stearoyl lactylate; and (d) asource of fat characterized by the ratio, by weight, of the sum of then-6 fatty acids to the sum of the n-3 fatty acids being in the range ofabout 1.3:1 to 2.5:1; the nutritional product having a pH in the rangeof 6.4 to 6.6 and being a stable emulsion after being subjected toterminal sterilization.
 2. A nutritional product for enteral nutritionalsupport of a person infected with human immunodeficiency virus asdescribed in claim 1 where the source of fat comprises fish oil.
 3. Anutritional product for enteral nutritional support of a person infectedwith human immunodeficiency virus as described in claim 2 wherein theintact protein comprises sodium caseinate.
 4. A nutritional product forenteral nutritional support of a person infected with humanimmunodeficiency virus as described in claim 1 further comprising asource of dietary fiber.
 5. A nutritional product for enteralnutritional support of a person infected with human immunodeficiencyvirus as described in claim 4 wherein the intact protein comprisessodium caseinate.
 6. A nutritional product for enteral nutritionalsupport of a person infected with human immunodeficiency virus asdescribed in claim 4 wherein the source of dietary fiber comprises soypolysaccharides.
 7. A nutritional product for enteral nutritionalsupport of a person infected with human immunodeficiency virus asdescribed in claim 6 wherein the intact protein comprises sodiumcaseinate.
 8. A nutritional product for enteral nutritional support of aperson infected with human immunodeficiency virus as described in claim1 wherein the soy protein hydrolysate has a degree of hydrolysis in therange of about 14 to 17 and the amino acid profile of the soy proteinhydrolysate has less than 1% free amino acids.
 9. A nutritional productfor enteral nutritional support of a person infected with humanimmunodeficiency virus as described in claim 8 wherein the intactprotein comprises sodium caseinate.
 10. A nutritional product forenteral nutritional support of a person infected with humanimmunodeficiency virus as described in claim 1 wherein the intactprotein is selected from the group consisting of: sodium caseinates, peaprotein isolates and whey protein isolates.
 11. A nutritional productfor enteral nutritional support of a person infected with humanimmunodeficiency virus as described in claim 1 wherein the nutritionalproduct has a caloric density of about 1.2 to 1.35 calories per ml. 12.A liquid nutritional product for enteral nutritional support of a personinfected with human immunodeficiency virus comprising:(a) a first sourceof protein comprising a soy protein hydrolysate having a degree ofhydrolysis in the range of about 14 to 17 and a molecular weightpartition, as determined by size exclusion chromatography, wherein30-60% of the particles have a molecular weight in the range of1,500-5,000 Daltons and the amino acid profile of the soy proteinhydrolysate has less than 1% free amino acids; (b) a second source ofprotein which comprises sodium caseinate, the sodium caseinatecomprising by weight about 10-30% of the protein in the nutritionalproduct; (c) a source of diacetyl tartaric acid esters ofmono-diglycerides; and (d) a source of fat characterized by the ratio,by weight, of the sum of the n-6 fatty acids to the sum of the n-3 fattyacids being in the range of about 1.3:1 to 2.5:1; the nutritionalproduct having a pH in the range of 6.4 to 6.6 and being a stableemulsion after being subjected to terminal sterilization.
 13. Anutritional product for enteral nutritional support of a person infectedwith human immunodeficiency virus as described in claim 12 furthercomprising a source of dietary fiber.
 14. A nutritional product forenteral nutritional support of a person infected with humanimmunodeficiency virus as described in claim 12 further comprising soypolysaccharide as a source of dietary fiber.
 15. A nutritional productfor enteral nutritional support of a person infected with humanimmunodeficiency virus as described in claim 12 wherein the source offat comprises fish oil.
 16. A nutritional product for enteralnutritional support of a person infected with human immunodeficiencyvirus as described in claim 12 wherein the source of fat comprises fishoil, canola oil and medium chain triglycerides.
 17. A nutritionalproduct for enteral nutritional support of a person infected with humanimmunodeficiency virus as described in claim 12 wherein the nutritionalproduct has a caloric density of about 1.2 to 1.35 calories per ml. 18.A liquid nutritional product for enteral nutritional support of a personinfected with human immunodeficiency virus comprising:(a) a first sourceof protein comprising a soy protein hydrolysate having a degree ofhydrolysis in the range of about 14 to 17 and a molecular weightpartition, as determined by size exclusion chromatography, wherein30-60% of the particles have a molecular weight in the range of1,500-5,000 Daltons and the amino acid profile of the soy proteinhydrolysate has less than 1% free amino acids; (b) a second source ofprotein which comprises sodium caseinate, the sodium caseinatecomprising by weight about 10-30% of the protein in the nutritionalproduct; (c) a source of diacetyl tartaric acid esters ofmono-diglycerides; and (d) a source of fat comprising canola oil andfish oil characterized by the ratio, by weight, of the sum of the n-6fatty acids to the sum of the n-3 fatty acids being in the range ofabout 1.3:1 to 2.5:1, and (e) dietary fiber in the form of soypolysaccharide; the nutritional product having a caloric density in therange of about 1.2 to 1.35 calories per ml; the nutritional producthaving a pH in the range of 6.4 to 6.6 and being a stable emulsion afterbeing subject to terminal sterilization.
 19. A nutritional product forenteral nutritional support of a person infected with humanimmunodeficiency virus as described in claim 18, further comprisingβ-carotene.
 20. A nutritional product for enteral nutritional support ofa person infected with human immunodeficiency virus as described inclaim 18, further comprising per liter: (a) about 970 to 1020 mg ofsodium; (b) about 2600 to 2750 mg of potassium; and (c) about 1400 to1500 mg of chloride.